1. Field of the Invention
This invention relates to phase stable, liquid detergents, which contain essentially insoluble oxidants, which maintain good oxidative stability yet have surprisingly effective performance in fabric bleaching and cleaning.
2. Brief Description of Related Art
Liquid detergents are desirable alternatives to dry, granular detergent products. While dry, granular detergents have found wide consumer acceptance, liquid products can be adapted to a wide variety of uses. For example, liquid products can be directly applied to stains and dirty spots on fabrics, without being predissolved in water or other fluid media. Further, a "stream" of liquid detergent can be more easily directed to a targeted location in the wash water or clothing than a dry, granular product.
There have been many attempts to formulate liquid detergents which contain oxidants.
For example, Krezanoski, U.S. Pat. No. 3,852,210, Lutz et al., U.S. Pat. No. 4,130,501, and Smith et al., U.S. Pat. No. 4,347,149, disclose liquid hydrogen peroxide-based bleach compositions at relatively low pH's containing relatively minor amounts of surfactants. The disadvantage with these compositions would be rather low detergency, owing to the low amount of surfactants.
Franks, U.S. Pat. No. 4,430,236, Goffinet et al., U.S. Pat. No. 4,470,919, and Smith et al., U.S. Pat. No. 4,525,291, disclose higher amounts of hydrogen peroxide and surfactant. However, in order to preserve the oxidant, the compositions generally require the addition of stabilizing agents, such as a lower alcohol and an amino polyphosphonate (Smith et al.) or fatty acids and soluble calcium salts (Goffinet et al.).
Alkaline earth metal oxidants have been proposed in various dry detergent or bleach products, e.g., U.S. Pat. Nos. 3,230,171, 3,251,780, 3,259,584, 3,382,182, all to Moyer; Lippmann, U.S. Pat. No. 2,288,410; Blumbergs, U.S. Pat. No. 3,332,882, and German published patent application DE OS 35 34524.
However, none of the foregoing references, or a combination thereof, teaches, discloses or suggests that alkaline earth metal peroxides may be stably incorporated in a liquid detergent medium. None of the art further teaches that oxidant stability of such insoluble oxidant is maintained or that surprisingly effective cleaning performance is obtained therewith. Finally, none of the art teaches, discloses or suggests that relatively small amounts of an antioxidant are effective at stabilizing liquid detergents containing such insoluble oxidants.